Epidemiological profile and follow-up of patients with pulmonary disease by non-tuberculous mycobacteria in Baixada Santista area, São Paulo

Objective

To present the frequency and species diversity of non-tuberculous mycobacteria, estimate the prevalence of non-tuberculous mycobacterial pulmonary disease, describe the epidemiological profile, and determine the follow-up of patients with non-tuberculous mycobacterial pulmonary disease living in a region with a high burden of tuberculosis.

Methods

This a retrospective cohort observational study using data records obtained from the Instituto Adolfo Lutz - Santos and from the São Paulo Sistema de Vigilância de Tuberculose do Estado de São Paulo in the period between 2000 and 2009. The studied variables were: socio-demographic characteristics, current and past history of tuberculosis, aspects related to diagnosis, and treatment and associated diseases.

Results

We included 319 non-tuberculous mycobacteria isolates in the study, corresponding to 257 patients. The species Mycobacterium kansasii (28.5%) and Mycobacterium fortuitum (16.6%) presented the higher occurrence. In 10.9% (24) of the patients, there was a criterion for confirming a case of pulmonary disease due to non-tuberculous mycobacteria. In relation to gender and age, male and individuals over 50 years old were the most frequent. Considering the confirmed cases, 47.8% had a past history of tuberculosis.

Conclusion

The lack of information about the cases is evident, since pulmonary disease due to non-tuberculous mycobacteria is not mandatory. The therapeutic regimen according to the identified species is fundamental for success in combating the infections caused by non-tuberculous mycobacteria. Besides that, information about the regional epidemiology of pulmonary disease caused by non-tuberculous mycobacteria and the search for associations with other comorbidities are important to establish the correct treatment. In order to improve surveillance of pulmonary diseases by non-tuberculous mycobacteria, we suggest the implantation of a sentinel surveillance and of population-based studies.

Metal center ion effects on photoinactivating rapidly growing mycobacteria using water-soluble tetra-cationic porphyrins

Rapidly growing mycobacteria (RGM) are pathogens that belong to the mycobacteriaceae family and responsible for causing mycobacterioses, which are infections of opportunistic nature and with increasing incidence rates in the world population. This work evaluated the use of six water-soluble cationic porphyrins as photosensitizers for the antimicrobial photodynamic therapy (aPDT) of four RGM strains: Mycolicibacterium fortuitum, Mycolicibacterium smeagmatis, Mycobacteroides abscessus subs. Abscessus, and Mycobacteroides abscessus subsp. massiliense. Experiments were conducted with an adequate concentration of photosensitizer under white-light irradiation conditions over 90 min and the results showed that porphyrins 1 and 2 (M = 2H or Zn^II ion) were the most effective and significantly reduced the concentration of viable mycobacteria. The present work shows the result is dependent on the metal-center ion coordinated in the cationic porphyrin core. Moreover, we showed by atomic force microscopy (AFM) the possible membrane photodamage caused by reactive oxygen species and analyzed the morphology and adhesive force properties. Tetra-positively charged and water-soluble metalloporphyrins may be promising antimycobacterial aPDT agents with potential applications in medical clinical cases and bioremediation.

Mycobacterium abscessus urinary tract infection: case report

Urinary tract infection is a serious public health issue that predominantly affects women. In men, it is more often associated with prostatic hyperplasia and bladder catheterization. Urogenital tuberculosis presents with nonspecific with nonspecific symptoms and the diagnosis can be made in the presence of sterile leukocyturia and recurrent infection with acid urine. Non-tuberculous mycobacteria or other non-tuberculosis mycobacteria are opportunistic pathogens that inhabit the soil, water or environment surfaces, and usually cause diseases in immunocompromised individuals. Mycobacterium abscessus is an agent that causes lung, skin and soft tissue hospital infections. Urinary tract infections by this pathogen are rare.

The looming tide of nontuberculous mycobacterial infections in Portugal and Brazil

Nontuberculous mycobacteria (NTM) are widely disseminated in the environment and an emerging cause of infectious diseases worldwide. Their remarkable natural resistance to disinfectants and antibiotics and an ability to survive under low-nutrient conditions allows NTM to colonize and persist in man-made environments such as household and hospital water distribution systems. This overlap between human and NTM environments afforded new opportunities for human exposure, and for expression of their often neglected and underestimated pathogenic potential. Some risk factors predisposing to NTM disease have been identified and are mainly associated with immune fragilities of the human host. However, infections in apparently immunocompetent persons are also increasingly reported. The purpose of this review is to bring attention to this emerging health problem in Portugal and Brazil and to emphasize the urgent need for increased surveillance and more comprehensive epidemiological data in both countries, where such information is scarce and seriously thwarts the adoption of proper preventive strategies and therapeutic options.

Rate of tuberculosis infection in children and adolescents with household contact with adults with active pulmonary tuberculosis as assessed by tuberculin skin test and interferon-gamma release assays

Tuberculosis (TB) infection was evaluated in Brazilian immunocompetent children and adolescents exposed and unexposed (control group) to adults with active pulmonary TB. Both groups were analysed by clinical and radiological assessment, TST, QFT-IT and T-SPOT.TB. The three tests were repeated after 8 weeks in the TB-exposed group if results were initially negative. Individuals with latent tuberculosis infection (LTBI) were treated and tests were repeated after treatment. Fifty-nine TB-exposed and 42 controls were evaluated. Rate of infection was 69·5% and 9·5% for the exposed and control groups, respectively. The exposed group infection rate was 61% assessed by TST, 57·6% by T-SPOT.TB, and 59·3%, by QFT-IT. No active TB was diagnosed. Agreement between the three tests was 83·1% and 92·8% in the exposed and control groups, respectively. In the exposed group, T-SPOT.TB added four TB diagnoses [16%, 95% confidence interval (CI) 1·6-30·4] and QFT-IT added three TB diagnoses (12%, 95% CI 0-24·7) in 25 individuals with negative tuberculin skin test (TST). Risk factors associated to TB infection were contact with an adult with active TB [0-60 days: odds ratio (OR) 6·9; >60 days: OR 27·0] and sleeping in the same room as an adult with active TB (OR 5·2). In Brazilian immunocompetent children and adolescents, TST had a similar performance to interferon-gamma release assays and detected a high rate of LTBI.

In-house PCR with DNA extracted directly from positive slides to confirm or exclude the diagnosis of tuberculosis: focus on biosafety

The possibility to obtain DNA from smears is a valuable alternative to remedy the lack of samples when they are totally used for bacilloscopy; this technique solves the biosafety problem related to a possible accident with the transportation of flasks containing potentially transmissible clinical samples. Hence, the purpose of this study was to utilize the insertion sequence IS6110 for amplification of DNA from a smear-positive sample for tuberculosis (TB) diagnosis. Among the 52 positive bacilloscopies, sensitivity, specificity, positive predictive value and negative predictive value were 52.3%, 100%, 100% and 89.7%, respectively whereas accuracy was 90.7%. The IS6110-based PCR for TB diagnosis developed in DNA extracted from a positive smear is a fast, simple, specific, and safe method.